Boring machine with attachments



April 7, `1942. E. A. ARP

' BORING MACHINE WITH ATTACHMENT fn dentaria TA. Vl Om. H n m@ Qm.m.m Nm [vgl nm. DW n Nv a Patented Apr. 7, 1942 2,278,759 p BORING MACHINE WITH ATTACHMENTS Ewald A. Arp, Minneapolis, Minn., assignor to Tobin-Arp Manufacturing Company, Minnea-polis, Minn.,a copartnershipfconsisting of Wilbert J. Tobin, Ewald A. Arp, and Henry S. KedneyMinneapolis, Minn.

Application August 7, 1941, Serial No. 405,773

28 Claims.

This invention has relation to a boring machine with lattachment for clamping articles, such, for example, as connecting rods, in the boring machine so thatv inner bearing surfaces of n the -articles or connecting rods can be finished.

An object of the invention is to provide a boring machine with attachment of the nature as stated, designed to incorporate various improved features and characteristics of construction which will be novel both as individual entities of said boring machine with attachment and in combination with each other.

A further object is to provide a boring machine with attachment adapted to the purpose of postioning and clamping an article such as a connecting rod in said boring machine in novel and improved manner so that an internal bearing surface of said article or connecting rod can be `accurately nished.

And a further object is to provide a boring machine with attachment of construction as hereinafter explicitly set forth.

With the above objects in View, as well as others which will appear as the specification Iproceeds, the invention comprises the construction, arrangement and `combination of parts as now to be fully described and as hereinafter to be specifically claimed, it being understood that the disclosure herein is merely illustrative and intended e in no way in a limiting sense, changes in details of construction and arrangement of parts being permissible so long as Within the spirit of the invention and the scope of the claims which follow.

In the accompanying drawing forming a part of this specifi-cation,

Fig. 1 is a front elevational view of a boring machine with attachment made according to the invention;

Fig. 2 is a fragmentary horizontal sectional View, partially in elevation, of the machine with attachment of Fig. 1;

Fig. 3 is a fragmentary vertical sectional view, partially in elevation, of said machine with attachment of Fig. 1;

Fig. 4 is an enlarged fragmentary sectional view detailing the clamping nut` of the l:machine with attachment, as well as parts associated with said clamping nut;

Fig. 5 is an enlarged sectional view, taken on line -5-5 in Fig. 1; and

Fig. 6 is a detail sectional view on either of the lines 6 6 in Fig. 2.

With respect to the drawing and the numerals of reference thereon, a frame for the machine with attachment is denoted aty I0 and a support of said frame is `denoted at II. Only a part of the frame I 0 is disclosed, and that part includes 'an upright block, denoted I2, of metal having ya forward, desirably vertical, fiat surface I3. v

A cutter shaft I 4 ofthe boring machine is suitably and conveniently mounted, as at I5, for rotationaland endwisemovem'ent in the block I2, and said cutter shaft is disposed in right angle relation to the forward, at surface I3 of said block. The cutter shaft can be rotated and reciprocated in any ordinary or preferred manner, forming no part of the present invention. The front end portion of said cutter shaft is adapted to be projected to position beyond .the forward, iiat surface I3, as the cutter shaft is disclosed in the drawing, and a usual cutter I6 is adapted to vbe situated in a cross slot Il through said front end portion of said cutter shaft and to be releasably retained in said cross slot in any suitable and convenient manner, las by employment of a set screw I8. o

A backing member I9, adapted to be engaged by one surface of an article, such as -a connecting rod 20, to be operated upon in the machine, is inset into the forward, at surface I3 of the vblock I2 .and itself includes a forw-ard, flat surface 2| which is fas shown disposed slightly forwardly.. of and parallel to said surface I3. That is, the cutter shaft I4 is perpendicular to the forward, at surface 2|, vas Well as perpendicular to the forward, flat surface I3.

An article orl connecting rod positioner, denotedA generally at 22, is adapted to be actuated to cause an internal bearing surface of an article or connecting. rod to `be operated upon to be accurately centered inthe machine with respect to the -cutter shaft I4 and its cutter I6, and an article or connecting rod clamping device, repre-A sented generally at 23, is adapted to be actuated to cause an article or connecting rod, after centered by said positioner, to be rigidly clamped in its centered position against the .backing surface I9 and between said backing surface and the `clamping device 23. The positioner 22 is adapted to be removed from the machine after it has been actuated to center anarticle or connecting rod, as well as after the Iclamping device 23ohas been turned home, but before the commencement of the boring operation of the cutter I6 upon the internal bearing surf-ace of the centered article or connecting rod intended to finish said internal bearing surface. i

The clamping device 23 includes a pair of spaced apart, oppositely disposed trunnions 24l 24, each mounted for movement of rotation in :a bearing member supported upon the forward wall of the block I2. The trunnions 24 are alined with each other, and each extends horizontally outwardly away from its corresponding bearing member 25 to position spaced from the machine frame. The outer, end of each trunnion pivotally supports, as at 25, an intermediate portion of a vertically disposed lever 21. 'Ihe levers 21 are supported by the trunnions 24 for pivotal movement in a substantially vertical plane.

The lower end portion of each vertical lever 21 is pivotally connected, las at 28, to the adjacent end of a substantially horizontal, inwardly extending link 29, and the opposite or inner end of each link 29 is pivotally connected, as at 30, to a clamping nut 3|.

The clamping nut 3i is rotatably mounted against endwise play or movement upon the outer surface of an internally threaded tubular element 32 itself threadably mounted upon a horizontal externally threaded member 33 fixed in the machine frame as at 34. A spring pressed friction element 35 in the clamping nut 3l and engaged against the external surface of the tubular element 32 is for a purpose to be made plain. A lug `36'upon an arm 31 of said clamping nut 23 and'adapted to engage one of the links 29 is also for a purpose to be set forth. Means for rotating the tubular element 32 upon the threaded member 33, thus to cause said tubular element and the clamping nut 3l to be moved inwardly or outwardly of the machine, is constituted as an'operating handle 38 integral or rigid with the outer end of said tubular element.

The upper end portion of each vertical lever 21 includes an opening y3!! which loosely receives a horizontal guide rod 46. A nut '4I upon the forward end portion of each guide rod 46 is adapted to be engaged by the upper'end portion of the corresponding vertical lever 21, at location about the opening 3S, and lock nuts 42 upon the guide rods and engaged against'the nuts 4I are for insuring the set positions of said nuts.

An intermediate portion of each guide rod 4l] is slidably disposed in a guide way 43 of a corresponding guide 44, and each guide V44 isintegral or rigid with an inwardly extending, hori- 'zontally disposed strip 45 of rigid material `or metal slidably mounted in a horizontal guide channel 46 included in a forward portion of the machine frame. The guide channels 46 are in alined relation to each other at the opposite sides of and just forwardly of the'forward surface I3.

Each rigid strip 45 xedly supports, as at 41, an externally threaded member 48 which is 'perpendicular to the strip and extends horizontally outwardly away from the forward surface of the machine and is parallel with and in spaced relation to the guide rod 46 at the corresponding side of said machine. In turn, each externally threaded member 48 adjustably supports a tubular element 49 which is mounted upon the externally threaded member for adjustment longitudinally thereof. More explicitly, the tubular elements 43 are threaded upon the horizontal members 48.

Each tubular element 49 pivotally supports, as denoted generally at 56, an intermediate portion of a horizontal clamping lever 5I, and the 'construction and arrangement are such as to preclude longitudinal movement of each of the clamping levers 5I upon its corresponding tubular element 48.

The clamping levers 5I are disposed vin alinement with each other at diametrically opposite sides of an article or connecting rod when situated in the machine, and an inner surface 52 of the inner end portion of each clamping lever is adapted to be engaged against an outer portion of the surface of said article or connecting rod which is opposite the backing member I9. The surfaces 52 are diametrically opposite each other, with respect to the article or connecting rod, and the construction and arrangement are such that the inner ends of the clamping levers are at the outer side of and clear of the internal bearing surface of an article or connecting rod when clamped in the machine. See Fig. 2. The forward end of each guide rod 4B is pivotally secured, asat 53, between spaced apart ears 54 upon the outer end of the corresponding clamp ing lever 5I.

The article or connecting rod positioner 22 includes an expander 55 and a plurality of spreader elements 56. The expander 55 is constituted as `an annular body 51 and spaced apart extension portions 58 rigid with said annular body. Acentral longitudinal opening 59 through said annular ,body 5T is of 'diameter to be snugly slidably receivable upon the `cutter shaft I4, and the extension portions 58'are disposed to clear said cutter shaft. As shown, there are three spreader elements 56 spaced about the expander 55 at 120 degrees apart, and each spreader element includes a longitudinal slot 6i) slidably disposed upon the outer marginal portion of one of the extension portions 58 of the expander. The outer edge 6I of each extension portion 58 slants inwardly of the expander in direction away from the annular bodyof said expander, andsaid outer edges 6I are spaced equidistantly from the longitudinal axis of the expander. The spreader elements 56 are held to eachother andto the extension portions 58 of the expander 55 by an encircling coil spring 62, and the forward 'end portion 63 of each spreader element is adapted to enter the eye of an article or connecting rod to be centered so that an outer edge 64 of said forward end portion is engaged against the bounding surface of :said eye, while an edge 65 of the spreader element, at right angles to the edge v'64 and disposed rearwardly of the forward end portion 673, is engaged 'against the forward surface of said varticle or connecting rod, as clearly disclosed in Fig. 3. The encircling coil spring S2 normally retains the spreader elements in remote relation to said body portion 51 and engaged with portions of the edges 6I spaced from the body portion.

To center an article or connecting rod, the expander 55 is slid upon the cutter shaft I4 and urged in direction toward the article or conntcting rod, while said article or connecting rod is retained adjacent to or contiguous with thebacking member I9, untilthe forward end portions 63 of the spreader elements rst enter the eye of the article or connecting rod, the .edges 65 next engage the forward surface of said article or connecting rod, and the outer ,edges'64 finally engage against the bounding surface of said eye Iby reason of relative movement between the expander 55 and the spreader elements 56 caused by continued inward movement cf said expander after engagement of said edges 65 with the article or connecting rod, whichcontinued movement causes spreading action upon said elements 56. At the completion of inward movement of the expander 55, the article or connecting rod is ,releasably grippedibetween thebacking element |9 and the edges B5,- and is also centered the clamping device is turned home, and said positioner willi-,then be removed before the boring operation upon an article or connecting rod is commenced. The clamping device 23 is adapted to be actuated to cause an article or connecting rod to be clamped in the machine or released therefrom by rotation ofthe operating handle 38.- Assum-` ing said clamping device turned home sothat an article or connecting rod, is clamped in the machine between the backing member` I9 and the surfaces 52 of the clamping levers 5|, rotation of said operating handle 38 toward the left in Fig. 1 will causeysaid surfaces 52 to be moved .both away from and clear of said article or con-.-

necting rod.- With turning movement of the operating handle toward the left, the tubular element 32 will be rotated and moved outwardly of the frame with resultant movement of the surfaces 52 to released position of the article or connecting rod, and when said .surfaces 52 release said article or connecting rod, the spring pressed friction element 35 will cause the clamping nut 3| to rotate with said tubular element 32 to cause the lug 36 to be removed from engagement with the underside of one of the links 29 and an arm 68 of the clamping nut to become engaged with a stop 69 upon the machine frame. Such movement of said clamping nut Willcause the pivotal connections 30, fto be moved toward the center of the machine, thus to cause the guide rods 40, the strips 45 and the clamping levers 5| to bemoved outwardly so that said clamping levers and their surfaces 52 are clear of said article or connecting rod and at the opposite sides thereof. Assuming the clamping device in released position, with the lug 36 spaced from the link and the arm 68 engaged with the stop B9 and the clamping levers disposed clear of an article or connecting rod inserted in the machine to be clamped, rotation of the operating handle 38 toward the right will first cause vthe clamping nut 3| to be rotated, by reason of the friction exerted by the spring-pressed element 35, until the links 29, 29 are in alinement and the lug 36 engages a link, thus to cause the surfaces 52 to be moved into position directly in front of the side surfaces'of the article or connecting rod, and continued rotation of said operating handle 38 toward the right will` cause said surfaces 52 to be turned down against' said article or connecting rod. Clearly, movement of the pivotal connections 30, 30 inwardly of the machine causes outward movement of the upper ends of the vertical levers 5|, and vice versa. Inward and outward pivotal movements' of the. vertical levers are of course about the pivotal connections 26. With inward and outward movement of the clamping nut 3| the links 29 are moved toward and away from the machine frame to cause the lower end portions of the vertical levers 21, 21 to .be moved in the same direction, with rotation of the trunnions 24, 24 in their bearings. Movement of said lower ,end portions of the vertical levers ,21, y21 in direction toward the machine frame causes the surfaces 52, 52 to'be moved to-y ward the article or connecting rod,jand-vi'ce versa; j. :f f

The' elements 49 are ad'justablejon lthe -members 48 in order that said elements 49 can be set `closer in when a thinner article or. yconnecting rod is'to be clamped 'and farther .out when the machine. is to vreceive a thicker `article or'.con-

ynecting, rod. Desirably, the trunnions 24 are adjustable longitudinally in the `bearing members 25,s o that the machine can accommodate articles or, connecting rods of different widths or diameters. Asl disclosed, a set screw 61 xes the position of each trunnion 24 within its bearing vmember 25and adjustment ofthe trunnions in directionlengthwise thereof can be` readily accomplished vbyfcausing the set screws tobe released from the trunnions. The pivotal connections 30, 30'are at the inner ends of lthe varms 31 and 68 so that the links 29, 29'Will be moved'inwardly bodily with: inward movement of the clamping nut 3|, aswill be understood. What is claimed is:

1. In a machine for boring an internal bearing of an article such as a connecting rod, a cutter Shaft adapted to be reciprocated and rotated, ka cutter carried by said cutter shaft, andmeans for releasably securing said article in centered position including a backing'member adapted to be engaged by a surface. of said article, spaced apart levers .having clamping surfaces thereof adapted to be releasably engaged against a surface of the article opposite said backing member, and mechanism for simultaneously actuating said levers to cause their clamping surfaeesto be pressinglyfengaged` with and released and withdrawn vfrom said article. i

2. In a machine for boring an internal bearing ofan article such as a connecting rod', a cutter shaft adapted to bel reciprocated and rotated, a cutter carried by said cutter shaft, positioning means for centering said article with respect to said outer shaft and cutter, and means for releasably securing said. article in centered position including a backing memberv adapted kto be engaged by a surface of said article, spaced apart levers having clamping surfaces thereof adapted to be releasably engaged against spaced apart portions ofk a surface of thearticle opposite said backing member and in spaced relation to said internalbearing, mechanism for simultaneously actuating said levers to cause their clamping surfaces to be concurrently pressingly engaged4 with and released and withdrawn from said'article, and unitary means for actuating said mechanism. 3. In a machine for boring an internal bearing of an article such as a connecting rod, a cutter shaft adapted to be reciprocated and rotated, a cutter vcarried by ksaid cutter shaft, positioning means for centering said article with-respect to said cutter shaft and cutter, and means for re-l leasably securing said article in centered position including a backing member adapted to be engaged by a" surface of said article at location spaced fromsaid internal bearing, spaced apart levers having clamping surfaces thereof adapted to 'be releasably engaged against spaced-apart portions of asurface of thev article opposite said .backing member and in spaced relation to said internal bearing, and mechanism for simultaneously actuating said levers to cause their clamping surfaces to be yconcurrently pressingly 'engaged'with and released andfwithdrawn from said'article. Y

4; In amachine for boring an internal 'bearing' of an Varticle such asa connecting rod, a cutter shaft adapted to be reciprocated and rotated, a cutter carried by said cutter shaft,\positioning means for centering -said article with respect to said cutter shaft and cutter,and meansfor releasably securing said Aarticlein centeredpositionk includingI :a backing member adapted -to be engaged by a surface of said article, spaced apart levers havingclamping surfaces' thereof adapted to be releasably engaged against spacedapart portions of a surface of the article opposite said backing. member and in spaced relation to. said internal bearing, and mechanism for simultaneously actuating said levers to cause theirclamping surfaces to. Vbe concurrently pressingly* engaged with said spaced apart'portions of said surface of said article and-simultaneously released from the spaced apart portions ofthe surface and withdrawn to clearing relation of said article.

5. In a machine for boringan interna1 bearing of an article such as a connecting rod, a -eutter shaft adapted to be reciprocated and rotated, a cutter carried by said cutter shaft, and4 means for releasably securing, said article in `centered position including a backing member adapted to be engaged by a surface ofsaid article in spaced relation to said internal bearing, spaced apart levers having clamping surfaces thereof adapted to be releasably engaged against spaced apart portions of a surface of the article opposite said backing member and inspaced relation Ato said internal bearing, an entity adapted to be actuated to cause the clamping surfaces of said levers to be concurrently pressingly engaged against said spaced apart portions of said surface of said article and to be concurrently released from the spaced apart portions of the surface and withdrawn from the article, and means for actuating said entity.

6. Ina machine for boring an internal bearing of an article such as a connecting rod, a cutter shaft adapted to be reciprocated and rotated, .a cutter carried by said cutter shaft, positioning means for centering said article with respect'to said cutter shaft and cutter, and means for releasably securing said articlein centered position including a backing member adapted to be engaged by a surface of said article, spaced apart levers having clamping surfacesv thereof adapted to be releasably engaged against spaced apart portions of a surface of the article opposite said backing member and in spaced relation'to said internal bearing, and an entity adapted to vbe rotated to cause the clamping surfaces of said le-v vers `to be concurrently pressingly engaged against said spaced apart portions of said surface of said article with rotation of said entityin one direction and to be concurrently released from the spaced apart portions ofthe surface and Withdrawn from the a-rticle with rotation of said entity'in opposite direction.

7. In a machine'for Aboring vaninternal bearing of an article such as a connecting rodya cutter shaft adapted to be reciprocated and rotated, a cutter carried by said cutter shaft, `positioning means for centering said article with respect to said cutter shaft and cutter, and means for releasably securing said article in centered position including a backingmember adapted to be engaged by a surface of said article inspaced relation to said internalbearingfspaced apartievers having clamping 'surfaces thereof adaptedtoibe releasably engaged against spaced apart portions of a surface of the article opposite said backing member and inn spaced relationk to said'v-internal bearing, and-an entityincluding an actuating nut and'a link device adaptedto be actuated to .cause the clamping surfaces of-said levers to be moved yin a straight path toward and against said article when said actuating nut is caused to be moved in one direction and to be releasedrfrom said article and withdrawn from the location of the article when said actuating nut is caused to be moved in a different direction.

8. In a machine for boringran internal bearing of Aan article such as a connecting rod, a cutter shaft adapted tobe reciprocated and rotated, a cutter carried by said cutter shaft, positioning means for centering said article with respect to said 'cutter shaft .andfcutten` and means forreleasably securing said article -in centered position including a backingmember adapted to beengaged by a surface of said article, spacedapart levers having clamping surfaces thereof adapted to .be releasably engaged against spaced apart portions of a surface of the article opposite said backing member andinspaced relation to said internal bearing, `.and anentity including anactuating nut and a link` device adapted to be ,operated to cause the clamping surfaces of said levers to be rst lnovedto' the location of said article and then moved in a straight path. toward and against said articlewhen said actuating nut is caused to be moved in onedirection and to be released fromsaid article and Withdrawn from the location of the article when said actuating nut is caused to be moved in a different direction.

9. In a machine for boring an internal bearing 'A of an article such as a connecting rod, a cutter shaft adapted to be reciprocated and rotated. a cutter carried by said cutter shaft, positioning means for centering said article with respect to said cutter shaft and cutter, and means for releasably securing said article in centered position including a backing member adapted to be engaged with a surface of said article, spaced apart levers having clamping surfaces thereof adapted to be releasably engaged against spaced apart portions of a surface ofthe article opposite said backing member and in spaced relation to said internal bearing, and mechanism for simultaneously actuating said levers to cause their clamping surfaces to be moved toward and away from each other and at angular relation to the direction in which said clamping surfaces are moved toward and away from each other and concurrently pressingly engaged with and released and Withdrawn from said article.

10. In a machine for-boring an internal bear'- ing of an article such asa connecting rod, a cutter shaft adapted to be'reciprocated and rotated, a cutter carried by said cutter shaft, positioning means for centeringsaid article with respect to said cutter shaft and cutter, and means for releasably securing Vsaid article in centered position including a backing member adapted to be engaged by a surface'of said article in spaced relation to said internal bearing, spaced apart levers having clamping surfaces thereof adapted to be releasably engaged against spaced apart portions of a surface of the article opposite said backing member and'in spaced relation to said internal bearing, mechanism for simultaneously actuating said levers 'to cause their clamping surfaces to be moved toward and vaway from eachother and at angular-relation 4to the direction in which said clamping surfaces are moved toward and away yfrom each other and concurrently pressingly engaged with said spaced apart portions4 of saidsurfaceof said article andsimultaneously released fromthe spaced apart porra cutter carried by said cutter shaft, positioning means for centering said article with respect to said cutter shaft and cutter, and means for releasably securing said article in centered polsition including a backing member adapted to be engaged by a surface of said article, spaced apart levers having clamping surfaces thereof adapted to be releasably engagedvagainst spaced apart portions of a surface of the article opposite said' backing member and in spaced relation vto said internal bearing, and an entity including an actuating nut and a link device adapted to be operated to cause the clamping surfaces of saidv levers to be moved toward and away from each other and at angular relation tothe direction in which said clamping `surfaces are moved toward and away from each other with rotation of the actuating nut in oppositeadirections and kcon-Y currently pressingly engaged with said spaced apart portions of said surface of said article and simultaneously released lfrom `the spaced apart portions and withdrawn to clearing -relaf tion of the article.

12. In a machine for boring an internal bearing of an article such as a connecting rod, a cutter shaft adapted to. be reciprocated and rotateda cutter carried by said cutter shaft, Vpositioning means for centering' said article with respect to said cutter shaft and cutter,'and means for releasably securing said article in centered position including a backing member adapted to be engaged by a surface of said article, spaced apart levers having clamping surfaces thereof adapted to be releasably engaged against spaced apart portions of a surface of the article opposite said backing member and yin spaced Irelation to said internal bearing, a clamping'nut, and

link devices betweenk said spaced apart levers and said clampingvnut.

v13. In a machine for boring an internal bearing of an article such as a connectingV rod, a cutter shaft adapted to be reciprocated and rotated, a cutter'carried by said cutter shaft, positioning means for centering said article ,with respect to said cutter and cutter shaft, andmeans for releasably` securing said article incentered a lclamping lever pivoted 'upon said strip and in` cluding a clamping surface `at one side of its axis, a guide upon :said strip, a guide rod slidably mounted in said guide and pivotally connected to a portion of said clamping lever at the sideof its axis opposite its clamping surface, an element fixed upon said guide rodbetween 'said strip and clamping lever,'a trunnion, an actuating lever having an intermediate portion thereof pivotally supported upon said trunnion for universal movement of the actuating lever, said actuating lever having an end portion thereof loosely arranged upon said guide rod between said nxed element and said strip, an actuating nut upon said frame, and a link pivoted to said actuating nut and to an end portion of said actuating lever i at the side of said trunnion opposite saidI guide;

rod.

15. In a machine of the character described, a frame, guide means upon said frame, a strip of material slidably mounted in said guide means, a clamping lever pivoted upon said strip and including a clamping surface at one side of its axis, a guide upon said strip, a guide rod slidably mounted in said guide and .pivotally connected to a portion of said clamping lever at the side of its axis opposite its clamping surface, an element xed upon said guide rod between said strip and clamping lever, a trunnion, an actuating lever having an intermediate portion thereof pivotally supported upon said trunnion for universal movement of theactuating lever, said actuating lever having an end portion thereof loosely arranged upon said guiderod fbetween said fixed elementand said strip, an actuating nut upon said frame, a link pivoted to said actuating nut and `to an end I portion of said actuating lever at the side of said position including a backing member adapted to be engaged by a surfacejof saidf'article, spaced apart levers having clamping' surfaces .'.tl'iereof adapted to be releasably V-engaged againstspaced apart portions fof ajsurface of. the article opposite said backing member'and vinv spaced relation togsaid internal bearing, a clamping nut, and

linkY devices'between said spaced .apart leversy and said clamping nut, said Vclamping nutvbeing adapted to be actuated in opposite directions to causetheclamping surfaces/of said levers to'be,

moved toward and away fromveach therandat angular relation to the direction in which .said

clamping surfaces aremoved toward van'dfaway from eachother and to be concurrently pressingly engaged against said spaced apartfportions of said surface of said article and simultaneously released from ,thespace'd apart'k portions. and Withdrawn toelearing relation of the article. .a ,14; `Ina; machine 101"V Ithecharacter described,

a; frame, jguide means'` upon! said frame,.- aQstrip ofmaterial slidably mounted in 'said guide means.

otally connected to a portion, of one of said clamping levers at the side of its axis opposite its cla-mping surface, van element iixedupon each of said guide rods between the corresponding strip and clamping lever, oppositelydisposed trunnions, oppositely ydisposed actuating levers including an actuating lever having an intermediate portion thereof `pivotally supported upon each of said trunnions foruniver'salmovement of the actuating lever, each of saidactuating levers including an end portion vthereofloosely arranged upon one of said guide rods between the corresponding fixed element and strip, an actuating nut upon said frame, and links pivoted upon said actuating. nut and pivotally connected to end portions vof said actuating levers at thesdes of saidA trunnions opposite said guide rods.

17. In a machine of the character described, a

frame, oppositely disposed lguide channels upon,-

said frame, astrip of material slidably mounted in each of said guide channels, a clamping lever axis, a guide upon each of said strips, a guide rod slidably mounted inl each of said guides and pivotally connected to a portion of one of said clamping levers at the side of itsfaxis' opposite'its clamping surface, an element fixed upon each of said guide rods between the corresponding strip and clamping lever, oppositely disposed trunnions, oppositely disposed actuating levers including an actuating lever having an inter-v mediate portion thereof pivotally supported upon eachpf said trunnions for universal movement of the actuating lever, each of said actuating levers including an end portionthereof loosely arranged upon one of said guide rods between the corresponding fixed element and strip, a'threaded member upon saidv frame, a member upon said threaded member adapted to be moved inwardly of the frame with rotation ofthe member in one direction and outwardly of said frame with rotation of the member in opposite direction, a nut rotatable with and upon said member, links pivoted upon said nut and pivotally connected to endr portions of said actuating levers at the sides of said trunnions opposite said `guide rods; friction producing means between said nut and said membenan arm upon said nut adapted to engage one of said links, a stop upon said frame, and

means upon said nut adapted to engage-said stop.

18. YIn a Amachine of the character described, a frame, oppositely disposed guide channels upon said frame, a stri-p of material slidably -mounted in each of said guide channels, a clamping lever pivotally supported upon each of saidl strips and' including a clamping surfacer atone side of its axis, a guide upon each of said strips, a guide rod slidably mounted in each of said guides and pivotally connected to a vportion of one: of said clamping levers -at the side'of its axis opposite its clampingsurface, an element fixed uponeach of said guide rods between the corresponding strip and clamping lever, oppositely disposed trunnions, oppositely disposed. actuating levers including an actuating lever having an intermediateA portion thereof pivotally supported "upon each of said trunnions for universal movement of the actuating lever, each of said actuating levers -in cluding an end-portion thereof lloosely arranged upon one of said guide rods vbetween the corre-- spondingV fixed element and strip, a-threaded member upon said frame, a member-upon saidY threaded member adapted to be moved inwardly of the frame with rotation of said member in one.

direction and outwardlyof said frame with rotation of the member in opposite direction, a nut= rotatable with and upon said member, links piv` oted upon .said nut and pivotally connected -to end portions of said actuating levers at the sides of said-levers opposite said guide rods, friction producing means between said nut and said mem-- ber, arms upon said nut includin-g anfarm adjacent the outer side of eachof said links at location spaced outwardly of the pivotal connections between the nut and the links, oneof said arms. including means adapted. to engagev one of said.

links Yto preclude rotation of said nut with said member, and a stop upon said frame adapted to be engaged by one of said arms to preclude rota-- tion of the nut with the member, said nut being adapted to have limited movement of rotation with said member.

19. In a machine for boring an internal bearing of an article such as a connecting rod,.a cutter shaft adapted to be reciprocated and rotated, a cutter carried by said cutter shaft, positioning means for centering said article with respect to said cutter'shaft and cutter, and means for releasably securing said article in centered position including a backing member adapted to be engaged by a surface of said article, spaced apartA levers having clamping, surfaces thereof adapted to be releasably engaged against a surface of the article opposite said backing member, mechanism for actuating said leversv to cause their clamping surfaces to be simultaneously pressingly engaged with and released and Withdrawn from said article, and -means for actuating .said mechanism.

20. In a machine for kboring an internal 4bearing of an article such as a connecting rod, a cutter shaft adapted to be reciprocated and rotated, a cutter carried by said cutter shaft, positioning means for centering said article with respect to saidcutter shaft and cutter, and means for releasably securingsaid article in centered position including a backingmember adapted to be engaged by a surface of said article, spaced apart levers havingv clamping surfaces thereof adapted to be .releasably engaged against spaced apart portions of a surface of the article opposite said backing member and in spaced relation to said internal bearing, mechanism for simultaneously actuating said levers to cause their clamping surfaces to be concurrently pressingly engaged with said spaced apart portions of said surface of said article and simultaneously released from the spaced apart portions of the surface and withdrawn to clearing relation of said article, and means for actuating said mechanism. l

21. In a machine for boring an internal bearing of an article such as a connecting rod7 acutter shaft adapted to be reciprocated and rotated, a cutter carried by said cutter shaft, positioning means for centering said article with respect to said cutter shaft and cutter, and means for releasably securing said article in centered position including a backing member adapted to be engaged by a surface of said article, spaced apart levers having clamping surfaces thereof adapted to be releasably engaged againstspaced apart portions of a surface of the article opposite said backing member and in spaced relation to said ter shaft adapted to be reciprocated and rotated,

a cutter movable with said cutter shaft, and means for releasably securing said -article in centered position relatively to said cutter shaft and cutter including Va backing member having a'surface thereof disposed perpendicular to saidl cutter shaft adapted `to be engaged by asurface of said article, spaced apart clamping levers adapted to be engaged against thesurface of the article opposite said backing member, mechanism for actuating said clamping levers, and means for actuating said mechanism.

23. In a machine for boring an internalbearing ofan article such as a connecting rod, a cut-V ter shaft adapted to be reciprocated and rotated,

a cutter carried by said cutter shaft, positioning means for centering. said article with respect to said cutter shaft and cutter, and meansforlreleasably securing said article in centered `position including a backingmember having a sur- 24. In a machine for boring an internal bear ing of an article such as a connecting rod, a cutter shaft adapted to be reciprocated and rotated, a cutter movable with said cutter shaft, and means for releasably securing said article in centered position relatively to said cutter shaft and cutter including a backing member having a surface thereof disposed Vperpendicular to said cutter shaft adapted to be engaged by a surfacey of said article, and a clamping device including spaced apart clamping levers adapted to be engaged against a surface of the article opposite said backing member, and mechanism for simultaneously actuating said clamping levers.

25. In a machine for boring an internal bearing of an article such as a connecting rod, a

f cutter shaft adapted to be reciprocated and rotated, a cutter carried by said cutter shaft, and means for releasably securing said article in centered position relatively to said cutter shaft and cutter including a backing member having a surface thereof disposed perpendicular to said cutter shaft adapted to be engaged by a surface of said article, spaced apart levers having clamping surfaces thereof adapted to be releasably engaged against a surface of the article opposite said backing member, and mechanism for simultaneously actuating said levers to cause their clamping surfaces. to be pressingly engaged with and released from said article.

26. In a machine for boring an internal bearing of an article such as a connecting rod, a cutter shaft adapted to be reciprocated and rotated, a cutter carried by said cutter shaft, positioning means for centering said article with respect to said cutter shaft and cutter, and means for releasably securing said article in centered position including a backing memberhaving a surface thereof disposed perpendicular to said cutter shaft adapted to be engaged by a surface of said article, spaced apart levers having clamping surfaces thereof adapted to be releasably engaged against a surface of the article opposite said backing member, mechanism for actuating Vsaid levers to cause their clamping surfaces to be simultaneously pressingly engaged with and released and `Withdrawn from said article, and

y means for actuating said mechanism.

27. In a machine for boring an internal bearing of an article such as a connecting rod, a cutter shaft adapted to be reciprocated and rotated, a cutter carried by said cutter shaft, and means for releasably securing said article in centered position relative to said cutter shaft and cutter including a backing rmember, having a surface thereof disposed perpendicular to said cutter shaft adaptedto be engaged by a surface of said article, spaced apart levers having clamping surfaces thereof adapted to be releasably engaged against spaced apart portions of a surface of the article opposite said backing member and in spaced relation to said internal bearing, mechanism for simultaneously actuating said levers to cause their clamping surfaces to be concurrently pressingly engaged With said spaced apart portions of said surface of said article and simultaneously released from the spaced apart portions of the surface and Withdrawn to clearing relation of said article, and means for actuating said mechanism.

28. In a machine for boring an internal bearing of an article such as a connecting rod, a cutter shaft adapted to be reciprocated and rotated, a cutter carried by said cutter shaft, and means for releasably securing said article in centered position relatively to said cutter shaft and cutter including a backing member having a surface thereof disposed perpendicular to said ,cutter shaft adapted to be engaged by a surface of said article, spaced apart levers having clamping surfaces thereof adapted to be releasably engaged against spaced apart portion of a surface of the article opposite said backing member and in spaced relation to said internal bearing, mechanism adaptedto be actuated to cause the clamping surfaces of said levers to be concurrently pressingly engaged against said spaced apart portions Qf said surface of said article and to be concurrently released from the spaced apart portions of the surface and Withdrawn from the article, and means adapted to be rotated in opposite directions for actuating said mechanism.

EWALD A. ARP. 

